Probably my favorite:
natashaskitchen.com

Prep time: 20 minutes
Cook time: 1 hour
Total Time: 1 hour 20 minutes
Servings: 6

INGREDIENTS:

Meat Loaf Recipe:

• 2 lbs ground beef, 85% or 80% lean*
• 1 med onion, (1 cup), finely chopped
• 1 tsp olive oil
• 2 large eggs
• 3 garlic cloves, minced
• 2 Tbsp ketchup
• 3 Tbsp fresh parsley, finely chopped
• 3/4 cup Panko breadcrumbs, or gluten-free bread crumbs
• 1/3 cup milk
• 1 tsp salt, or to taste
• 1 tsp Italian seasoning
• 1/2 tsp ground black pepper

Meatloaf Sauce Ingredients:

• 3/4 cup ketchup
• 1 ½ tsp white vinegar
• 2 Tbsp brown sugar
• 1/2 tsp garlic powder
• 1/2 tsp onion powder

DIRECTIONS:

• Prep – Line a rimmed baking sheet with parchment paper or foil for easier cleanup, and preheat oven to 350°F.
• Sautee Onions – Set a medium skillet over medium heat. Add 1 tsp oil and chopped onion and saute, stirring occasionally, until softened and golden, about 5-7 minutes. Transfer to a plate to cool.
• Make the Meatloaf Mixture – In a large bowl, add all of the meatloaf ingredients and mix just until well combined (your hands are your best tool for mixing – put on disposable gloves if you want to).
• Shape Meatloaf and Bake – Add meat to the pan and shape it into a meatloaf about 8 inches long, 4 inches wide, and 3 inches tall. Bake uncovered at 350˚F for 40 minutes.
• Make the Sauce – In a small bowl, add the sauce ingredients and stir to combine.
• Add the Glaze – Spread the sauce over the Meatloaf, then return to the oven and bake an additional 20 minutes or until the internal temperature is 160˚F on an instant-read thermometer. Rest the meatloaf for 10-15 minutes before serving and it will be much easier to slice

NOTES:

• If you are baking this in a loaf pan, increase the heat to 375f. You may also need to adjust baking time.
• Don’t overmix the meatloaf or it’ll be more crumbly